$ { {4} \times \left[\begin{array}{rr}{0} & {0} \\ {2} & {-2}\end{array}\right] = {?} } $
Answer: To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rr}{4}\times{0} & {4}\times{0} \\ {4}\times{2} & {4}\times{-2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{0} & {0} \\ {8} & {-8}\end{array}\right]}$